Conventionally, there are known current constricted type semiconductor light emitting devices applicable to light sources for optical sensors.
In such a current constricted type semiconductor light emitting device, an electrode is disposed all over the top surface of a semiconductor layer, and an aperture is formed in the electrode. A point light source is configured to extract the light from the aperture. Since light generated at regions other than the aperture is shielded by the electrode, the light cannot be extracted therefrom and therefore is wasted. For this reason, in order to improve light extracting efficiency, an electric current is constricted so that the electric current may flow only in the region corresponding to a position of the aperture.
In such a current constricted type semiconductor light emitting device, the electric current is constricted, for example by doping impurities in the semiconductor layer (e.g., Refer to Patent Literature 1.).